Oxygen bleaching agents have become increasingly popular in recent years in household and personal care products to facilitate stain and soil removal. Bleaches are particularly desirable for their stain-removing, dingy fabric cleanup, whitening and sanitization properties. Oxygen bleaching agents have found particular acceptance in laundry products such as detergents, in automatic dishwashing products and in hard surface cleansers. Oxygen bleaching agents, however, are somewhat limited in their effectiveness. Some frequently encountered disadvantages include color damage on fabrics and damage to laundry appliances, specifically rubber hoses these appliances may contain. In addition, oxygen bleaching agents tend to be extremely temperature rate dependent. Thus, the colder the solution in which they are employed, the less effective the bleaching action. Temperatures in excess of 60.degree. C. are typically required for effectiveness of an oxygen bleaching agent in solution.
To solve the aforementioned temperature rate dependency, a class of compounds known as "bleach activators" has been developed. Bleach activators, typically perhydrolyzable acyl compounds having a leaving group such as oxybenzenesulfonate, react with the active oxygen group, typically hydrogen peroxide or its anion, to form a more effective peroxyacid oxidant. It is the peroxyacid compound which then oxidizes the stained or soiled substrate material. However, bleach activators are also somewhat temperature dependent. Bleach activators are more effective at warm water temperatures of about 40.degree. C. to about 60.degree. C. In water temperatures of less than about 40.degree. C., the peroxyacid compound loses some its bleaching effectiveness.
Attempts have been made to develop a bleach system which will be effective in lower temperature water conditions. U.S. Pat. No. 5,360,568 to Madison et al., U.S. Pat. No. 5,360,569 to Madison et al., and U.S. Pat. No. 5,370,826 to Madison et al., all relate to positively charged quaternary imine salts as catalysts for peroxygen compounds to transfer active oxygen and thus are said to increase the activity of peroxygen compounds over a range of water temperatures, including lower temperatures. However, these positively charged quaternary imine salts are not completely satisfactory in laundry bleaching applications. In particular, the positively charged quaternary imine salts disclosed in these references, when combined with peroxygen compounds, cause an unacceptable level of color damage on fabrics.
Accordingly, the need remains for an effective bleach boosting agent and composition containing bleach boosters which provides effective bleaching in lower water temperatures and provides improved color-safety profiles.